Fibrous infrared analysis

Graft and block copolymers of cotton cellulose, in fiber, yam, and fabric forms, were prepared by free-radical initiated copolymerization reactions of vinyl monomers with cellulose. The properties of the fibrous cellulose-polyvinyl copolymers were evaluated by solubility, ESR, and infrared spectroscopy, light, electron, and scanning electron microscopy, fractional separation, thermal analysis, and physical properties, including textile properties. Generally, the textile properties of the fibrous copolymers were improved as compared with the properties of cotton products. 

Kakudo and Kasai have summarized the central problem well ( ) "There are generally less than 100 independently observable diffractions for all layer lines in the x-ray diagram of a fibrous polymer. This clearly imposes limitations on the precision which can be achieved in polymer structure analysis, especially in comparison with the 2000 or more diffractions observable for ordinary single crystals. However, the molecular chains of the high polymer usually possess some symmetry of their own, and it is often possible to devise a structural model of the molecular chain to interpret the fiber period in terms of the chemical composition by comparison with similar or homologous substances of known structure. Structural information from methods other than x-ray diffraction (e.g., infrared and NMR spectroscopy) are also sometimes helpful in devising a structural model of the molecular chain. The majority of the structural analyses which have so far been performed are based on models derived in this way. This is, of course, a trial and error method". Similar perspectives have been presented by Arnott ( ), Atkins ( ), and Tadokoro... 

Hu, X., Kaplan, D. and Cebe, P. (2006) Determining beta-sheet crystallinity in fibrous proteins by thermal analysis and infrared spectroscopy. Macromolecules, 39, 6161-6170. 

Raman spectroscopy has been used to characterize organic fibers and films since the 1960s. Initially, Raman spectroscopy was used primarily to identify the material in the same way that infrared (IR) spectroscopy was used. Chemical identification and quantification are still used extensively to determine the type of polymer, the type and amount of comonomers, and the type and amount of pigments, dyes, or other additives. This has been used in forensic science, archaeology, competitive analysis, and quality control. The techniques are nearly identical to those used for the identification of other solids and liquids, with minor modifications required by the fibrous or filmlike nature of the materials. This application will be discussed in Section II,... 

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